The present invention relates to a novel process for the preparation of (S)- or (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid and to novel microorganisms capable of utilizing the propionamide of the formula 
in the form of the racemate or of its optically active isomers as the sole nitrogen source.
(S)-3,3,3-Trifluoro-2-hydroxy-2-methylpropionic acid is an important intermediate for the preparation of therapeutic amides (EP-A 0 524 781).
In the following text, 3,3,3-trifluoro-2-hydroxy-2-methylpropionic acid is abbreviated to 2,2-HTFMPS, and 3,3,3-trifluoro-2-hydroxy-2-methyl-propionamide to 2,2-HTFMPA.
In J. Chem. Soc., 1951, p. 2329 there is described a process for the preparation of (S)-2,2-HTFMPS where the corresponding racemate is converted into the desired (S) enantiomer by means of dimethoxystrychnine. The disadvantage of this process is that dimethoxystrychnine, which is employed for the racemate resolution, is too expensive.
EP-A 0 524 781 describes a process for the preparation of (S)-HTFMPS, in which the corresponding racemate is converted into the desired (S) enantiomer by means of (S)-(xe2x88x92)-xcex1-methylbenzylamine. The disadvantage of this process is that large amounts of (S)-(xe2x88x92)-xcex1-methylbenzylamine must be employed, which, again, makes this process too expensive.
It is an object of the present invention to provide an inexpensive, technically feasible process for the preparation of (S)- or (R)-2,2-HTFMPS.
This object is achieved by the microorganisms according to claim 1 and claim 11 according to the invention, the polypeptides according to claim 4 and by the processes according to claims 15 and 16.
Accordingly, the present invention relates to microorganisms selected from the wild, so-called xe2x80x9cwild typesxe2x80x9d, enzyme extracts therefrom, enzymes isolated therefrom having stereospecific amidohydrolase activity, and DNA/DNA fragments which are isolated from the xe2x80x9cwild typesxe2x80x9d and which encode a stereospecific amidohydrolase. The present invention furthermore relates to so-called genetically engineered microorganisms comprising these DNA fragments, or vectors. A further subject-matter is a process for the preparation of (S)- or (R)-2,2-HTFMPS and a process for the preparation of (S)- or (R)-2,2-HTFMPA using the above-described microorganisms.